Queue Watcher

The Queue Watcher module lets you define automatic checks
for specific queues regarding their overall size.

A queue might get bloated due to missing or too slow worker jobs.
With this module, you can define size limits a queue shouldn't exceed.
During each cron run, the Queue Watcher checks the sizes of the queues
and sends reports to certain E-Mail addresses
and the logging system in case of exceeded limits.

The module also adds some Drush helper commands, e.g.
$ drush queue-watcher-lookup

.. to get a list of currently existent queues with their states and for optionally sending reports to the configured recipients (mails and/or logs).

Furthermore you can see a status summary of your queue states in the status report.

Other useful modules

Queue UI, which can be used for directly viewing queues and processing them. Combining Queue Watcher and Queue UI together can provide a toolset for analysing, processing and reporting on problematic queues.